Location based services (LBS) targeted for consumers and enterprise applications have started gaining acceptance by the industry.
With the advancements in Global Positioning System (GPS) technology for mobile devices, the accuracy of mobile positioning systems has improved significantly, and consumer LBS applications such as mapping, local search, and real-time navigation are now available from mobile carriers and several other companies.
However, the ability to determine and to constantly maintain a current, real-time location is still not available on mobile devices, and mobile positioning systems and location based applications continue to rely on a pull or request based system, where an application or the system queries and gets a precise current location when it is required and requested.
In case of real-time applications such as turn-by-turn navigation, the current location is determined in real-time by requesting the location repeatedly and in frequent timing intervals for the duration such an application is in use.
However, such a pull or request based system does not maintain a precise current location of device at all times, and doing that in real-time imposes a significant drain of battery resources of the mobile device as well as imposes significant computing costs for the mobile positioning system.
Even in case of an E-911 scenario, if a device shuts down in an unforeseen event or a mishap, a precise current location may not be available, and only an approximate location of a user may be available for emergence response purposes. In such events, mobile carriers can determine an approximate location of the user based on cell-ID, however, a precise current or last known location that can only be determined by querying the device using a GPS or A-GPS solution, which may not be available if the device has already shut down.
In summary, to optimize the computing resources, the mobile positioning system operates as a pull or request based system, and a precise location is only determined when an application requests it. For applications where a precise and current location of a user is required at all times, the mobile positioning system must repeatedly query the device in order to maintain a current, real-time location of the user. With state of the art techniques, an application can specify the frequency or timing intervals of such requests, and can offload this process to another middleware service provider, which can notify the subscribing application(s) when the location changes. However, in order to maintain a precise, current location at all times, the GPS or A-GPS chipset embedded in the device has to be regularly polled, and the battery consumption continues to be a major constraint in enabling such real-time applications.